Powerless brake

Abstract

A motor brake includes an actuator fixed to a motor shaft and including spaced peripheral ears including a member therethrough. A fixed plate includes spaced detents and an output about the actuator has spaced ball releasably urged into the fixed plate detents by the actuator ear members. The output has channels for the actuator ears for driving the output with the actuator when the actuator ear members release the output spaced balls from the fixed plate detents.

What is claimed is: 
     
       1. A shaft brake comprising:
 a fixed plate; 
 an output flange releasably lockable with respect to the fixed plate and configured to be coupled to a structure to be driven by the shaft; and 
 an actuator driven by the shaft and configured to free the output flange from engagement with the fixed plate when the shaft turns, to then drive the output flange in rotation, and to position the output flange into locked engagement with the fixed plate when the shaft stops. 
 
     
     
       2. The brake of  claim 1  in which the fixed plate includes spaced detents therein. 
     
     
       3. The brake of  claim 2  in which the output flange includes spaced balls releasably received in said fixed plate spaced detents. 
     
     
       4. The brake of  claim 3  in which the actuator includes spaced members urging an output flange ball into a fixed plate detent when the shaft stops. 
     
     
       5. The brake of  claim 4  in which the actuator includes spaced ears and the output flange includes spaced channels receiving the spaced ears of the actuator for driving the output flange with the actuator. 
     
     
       6. The brake of  claim 5  in which the output flange spaced channels are configured to allow limited movement of the actuator spaced ears allowing limited rotation of the actuator with respect to the output flange. 
     
     
       7. The brake of  claim 6  further including one or more centering springs positioned to center each actuator ear in its respective output flange channel when the shaft stops. 
     
     
       8. The brake of  claim 7  in which the actuator spaced members are positioned to urge an actuator ball into a fixed plate detent when the actuator ears are centered in their respective output flange channels. 
     
     
       9. The brake of  claim 5  in which the actuator spaced members include a set screw extending through each or select actuator spaced ears. 
     
     
       10. A motor shaft brake comprising:
 a fixed portion; 
 an output releasably lockable with respect to the fixed portion and configured to be coupled to a structure to be driven by the shaft; and 
 an actuator rotatable with respect to the fixed portion and configured to release from and drive the output in rotation with respect to the fixed portion when the actuator is driven and, when the actuator stops, to lock the output with respect to the fixed portion. 
 
     
     
       11. The brake of  claim 10  in which the actuator includes spaced peripheral ears and the output includes spaced channels receiving the spaced ears of the actuator for driving the output. 
     
     
       12. The brake of  claim 11  in which the actuator spaced ears include a member extending therethrough. 
     
     
       13. The brake of  claim 12  in which the output includes balls corresponding to the ear members. 
     
     
       14. The brake of  claim 13  in which the fixed portion includes detents for the output balls. 
     
     
       15. The brake of  claim 11  in which the output spaced channels are configured to allow limited movement of the actuator spaced ears allowing limited rotation of the actuator with respect to the output. 
     
     
       16. The brake of  claim 10  further including means for centering the actuator with respect to the output when the actuator stops. 
     
     
       17. A shaft brake comprising:
 a fixed plate including spaced detants therein; 
 an output flange releasably lockable with respect to the fixed plate and including spaced balls releasably received in the fixed plate spaced detants; and 
 an actuator driven by the shaft and configured to free the output flange from engagement with the fixed plate when the shaft turns, to then drive the output flange in rotation, and to position the output flange into locked engagement with the fixed plate when the shaft stops. 
 
     
     
       18. The brake of  claim 17  in which the actuator includes spaced members urging an output flange ball into a fixed plate detent when the shaft stops. 
     
     
       19. The brake of  claim 18  in which the actuator includes spaced ears and the output flange includes spaced channels receiving the spaced ears of the actuator for driving the output flange with the actuator. 
     
     
       20. A brake comprising:
 an actuator with a stem fitted to a driven shaft and lobes extending radially outward from the stem; 
 an output about and driven by the actuator and including channels for the lobes; and 
 a fixed disk about the actuator and the output and releasably engaging the output when not driven by the actuator. 
 
     
     
       21. The brake of  claim 20  in which the output includes at least one ball releasably driven into a fixed disk detent by the actuator. 
     
     
       22. A motor shaft brake comprising:
 a fixed portion; 
 an output releasably lockable with respect to the fixed portion and including spaced channels; and 
 an actuator with spaced peripheral ears received in the spaced channels of the output and rotatable with respect to the fixed portion and configured to release from and drive the output with respect to the fixed portion when the actuator is driven and, when the actuator stops, to lock the output with respect to the fixed portion. 
 
     
     
       23. The brake of  claim 22  in which the actuator spaced ears include a member, the output includes balls corresponding to the ear members, and the fixed portion includes detents for the output balls. 
     
     
       24. A brake comprising:
 an actuator fixed to a motor shaft and including spaced peripheral ears each including a member; 
 a fixed plate including spaced detents; and 
 an output about the actuator and including:
 spaced balls releasably urged into the fixed plate detents by the actuator ear members, and 
 channels for the actuator ears for driving the output with the actuator when the actuator ear members release the output spaced balls from the fixed plate detents.